1. Department of Obstetrics and Gynecology; High Risk Pregnancy Unit; Dr. Zekai Tahir Burak Women's Health Care, Education and Research Hospital; Ankara Turkey
2. Department of Biochemistry; Gazi University Medical School; Ankara Turkey
3. Department of Biostatistics; Ankara University Medical School; Ankara Turkey
4. Department of Obstetrics and Gynecology; Gazi University Medical School; Ankara Turkey